Well my dear friends, It doesn't stop there.
In general cars don't wave to each other, and usually only when they know each other. Any vehicle can do the see someone you know BEEP BEEP wave, with an exception for maybe motorbikes, they do the BEEP BEEP waves swerve crash snap bleed burn crawl die.
Still following?
If you drive a van you'll get waves from other vans but not caravans, they are to high and mighty for the normal van, especially if it's a old person in a caravan. Trucks wave to trucks and solely trucks, although trucks will however beep at a signal from a pedestrian.
Getting more complex..
Buses wave to other bus drivers, they are like a big family. the salute from the steering wheel, or the serious stiff handed waves, are all traditional track/bus driver waves. Motorbike will nod to other motorbike with the occasional wave, this is dangerous (see previous point) and may cause waving issues i.e it's hard to wave with a broken wrist.
SUVs, Sedans, Hatchbacks and other assorted generic cars do not wave to one each other. Their wrists would be tired after about 5 minutes, There is just too many.
Normal waving is accepted in general but selective waving is going to earn you higher respect.
keep a look out for the types of waves in your area, and make your you use the right one, you don't want that random guy you'll never meet to think of you as some sort of bad waver.
Waving is a fun business.
Happy waving everyone.
